Superhard constructions & methods of making same

Abstract

A superhard construction comprises a substrate ( 10 ) comprising a peripheral surface, an interface surface ( 18 ) and a longitudinal axis and a super hard material layer ( 12 ) formed over the substrate and having an exposed outer surface forming a working surface ( 14 ), a peripheral surface extending therefrom and an interface surface. One of the interface surface of the substrate or the interface surface of the super hard material layer comprises one or more projections ( 24, 26 ) arranged to project from the interface surface, the height of the one or more projections being between around 0.2 mm to around 1.0 mm measured from the lowest point on the interface surface from which the one or more projections extend.

1 . A superhard construction comprising:
 a substrate comprising a peripheral surface, an interface surface and a longitudinal axis; and   a super hard material layer formed over the substrate and having an exposed outer surface forming a working surface, a peripheral surface extending therefrom and an interface surface;   wherein one of the interface surface of the substrate or the interface surface of the super hard material layer comprises:   one or more projections arranged to project from the interface surface, the height of the one or more projections being between around 0.2 mm to around 1.0 mm measured from the lowest point on the interface surface from which the one or more projections extend.   
     
     
         2 . The superhard construction of  claim 1 , wherein the height of the one or more projections is between around 0.3 mm to around 0.8 mm. 
     
     
         3 . The superhard construction of  claim 1 , wherein all or a majority of the interface surface between the spaced-apart projections is non-curved and extends in one or more planes which are not substantially parallel to the plane of the exposed outer surface of the super hard material layer. 
     
     
         4 . The superhard construction of  claim 1 , the substrate having a central longitudinal axis, wherein all or a majority of the interface surface between the spaced-apart projections extends in one or more planes which are not substantially parallel to a plane through which the central longitudinal axis of the substrate extends. 
     
     
         5 . The superhard construction of  claim 1 , wherein the projections are arranged in one or more substantially radial arrays around the central longitudinal axis of the substrate. 
     
     
         6 . The superhard construction of  claim 5 , wherein the projections are arranged in a first array and a second array, the second array being positioned radially within the first array. 
     
     
         7 . The superhard construction of  claim 6 , wherein the first and second arrays are substantially concentric with the substrate. 
     
     
         8 . The superhard construction of  claim 6 , wherein the first array comprises substantially double the number of projections than the second array. 
     
     
         9 . The superhard construction of  claim 6 , wherein the projections in the first and second arrays are staggered relative to each other. 
     
     
         10 . The superhard construction of  claim 1 , wherein the projections are randomly arranged on one of the interface surface of the substrate or the interface surface of the super hard material layer. 
     
     
         11 . The superhard construction of  claim 1 , wherein one or more of the surfaces of all or a majority of the projections extend in one or more planes which are not substantially parallel to the plane of the exposed outer surface of the super hard material layer and/or in one or more planes which are not substantially parallel to a plane through which the central longitudinal axis of the substrate extends. 
     
     
         12 . The superhard construction of  claim 1 , wherein the thickness of the super hard material layer about the central longitudinal axis of the substrate is substantially the same as the thickness of the super hard material layer at the peripheral surface. 
     
     
         13 . The superhard construction of  claim 1 , wherein the super hard material layer comprises polycrystalline diamond material and a plurality of interstitial regions between inter-bonded diamond grains forming the polycrystalline diamond material; the super hard material layer comprising:
 a first region substantially free of a solvent/catalysing material; and   a second region remote from the working surface that includes solvent/catalysing material in a plurality of the interstitial regions;   wherein the first region extends to a depth of greater than around 300 microns from the working surface into the body of polycrystalline diamond material.   
     
     
         14 . The superhard construction of  claim 13 , wherein the first region extends to a depth of between around 300 microns to around 1500 microns from the working surface into the body of polycrystalline diamond material. 
     
     
         15 . The superhard construction of  claim 13 , wherein the first region extends to a depth of between around 300 microns to around 1000 microns from the working surface into the body of polycrystalline diamond material. 
     
     
         16 . The superhard construction of  claim 13 , wherein the first region extends to a depth of between around 600 microns to around 1000 microns from the working surface into the body of polycrystalline diamond material. 
     
     
         17 . The superhard construction of  claim 1 , wherein the exposed outer surface of the super hard layer is substantially planar. 
     
     
         18 . The superhard construction of  claim 1 , wherein the one or more projections are of equal height. 
     
     
         19 . The superhard construction of  claim 1 , comprising a plurality of projections arranged in a first array and a second array concentrically located within the first array, wherein the projections in the first array are of a greater height than the projections in the second array. 
     
     
         20 . The superhard construction of  claim 1 , wherein any interface surface between any projections or not covered by the projections is uneven. 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . (canceled)